Liquid-contact switch



Aug. 27, 1929. A. M. nlsTELl 1,725,426

LIQUID CONTACT SWITCH Filed Deo. 22, 192s 60 :mw/waff Patented Aug. 2.7', 1929.

UNITED STATES PATENT oFFlcE.,M

ALFRED M. DISTELI, F OLTEN, SWITZERLAND, ASSIGNOR l'.130 R. W. CRAMER & COM- PANY, IN C., 0F NEW YORK, N. Y., A CORPORATION 0F NEW YORK.

LIQUID-CONTACT SWITCH.

Application led December 22, 1926, Serial No. 156,445, and inSwitzerland Horch 10, 1926.

This invention is a novel liquid contact switch, or mercury switch so-called, for making and-breaking an electric circuit or circuits.

The general objects of the invention consist in affording a mercury'switch which will be convenient and elicient in use, and which will be simple andv rugged in structure and not easily breakable. A further object is toprovide a contact makin and breaking device of this kind in which t e surface of liquid contact will be of relatively large area so as to give highly effective conduction. Other and further objects and advantages of the present in l5 vention will be explained in the hereinafter following descriptlon of an illustrative embodiment thereof or will be apparent to those conversant with the subject.

To the attainment of the aforesaid objects and advantages the present invention consists in the novel liquid contact switch, 'and the novel features of combination, arrangement, structure and design herein described or illustrated.

In the accompanying drawings Fig. 1 is a central longitudinal section of a liquid contact switch embodying the presentinvention.

Figs. 2 and 3 are detached views showing forms of apertured separatin wall which 3o may be employed in either o the embodiments of Figs. 1 or 4.

Fig. 4 is a view similar to Fig. 1 showing modilications of structure embodied in a multiple switch embodying the present invention.

Fig. 5 is a similar central section-showing a modified embodiment of certain features.

Fig. 6 is a ,transverse section showing a modification in the means of connecting the components of the device.

The illustrated embodiment is a mercury switch which comprises opposite containers or cups enclosing liquid chambers, and a wall separating thechambers, with a portion of the conducting liquid or mercury in each 45 chamber,circuit terminals for the respective chambers, and means whereby in one position the circuit is closed between the terminals through the mercury but is open' in another or the opposite position of the switch; the shift being made preferably by a bodily rotation ofthe assembled device. In the preferred embodiment the separating wall between the containers is apertured in such a manner that ins-one position the liquid portions unite to closethe circuit but are separated by the wall when the switch is in open positlon.

'I hus Fi ..1 shows a cup or container 10 which may e termed the outer cup, and oppos1te to it a second or inner cup or container 11,4 the two facing each other and being separated by a disk or wall 12. -In this embodiment the two containers are preferably constructed of conducting metal which is not subject to attack by mercury, such as iron, while the separating disk is of insulating material such as bakelite. The separating disk or wall is formed with an aperture 13 which is eccentric in position so that by revolving the switch the aperture can be brought to its higher level vas shown in Figs.l 1 and 2, thus separating'the conducting liquid, the lower edge of the aperture being shar ened or beveled at 14 to ass1st the separatlon. An advantageous shape for the communicating opening 13 is semiclrcular as shown in Fig.2, although the arrangement could be altered considerably, for

- example as with the disk 121 in 3 having a quadrant aperture 13a.

The first cup or container 10 is shown as provided with a trans arent or glass end wall 15. This serves the dbuble purpose of showing the position of the switch and of inspecting the condition of the interior elements. In some cases vthe glass wall can be dispensed with and indicating marks or words applied to the switch to show which position it occupies. The glass end plate 15 is shown clamped to the cup by a ring 16 secured tightly in place by screws 17, w1th washers interposed to prevent passage of liquid.

There may be a terminal post or screw 18 mounted directly in the metal of the first or outer cup 10 and a similar post or screw 19 on the cup 11, these adapted to receive the wires 20 constituting part of the circuit which is to be opened and closed by the switch. The

container 11, opposite to the glass plate 15, isl

closed by an integral end wall 21.

This described structure provides two i11- terior liquid chambers 23 and 24 in the containers 10 and 11 respectively. A body of mercury 25 is shown contained in the chamber 23 and a similar ortion of mercury 26 in the chamber 24. he total quantity of mercury is such that when the switch is reversed or inverted the mercury will pass through the aperture 13 and unite the two conducting character, but Such as to protect and minimize oxidization of the mercury. In lieu of oil a chemically inert gas could be substituted, such as helium, or a vapor.

The three main elements 10, 11 and 12,

with the mercury contained therein, consti-4 tute an assemblage which may be firmly and permanently secured into an entity in various ways, for example by longitudinal screws 29 or the like adapted-to cause the two containers to be drawn firmly together in a liquid tight manner against the separating disk. Each of the screws 29 is shown as surrounded by an insulating bushing 30 and provided with an insulating washer 31 so as to avoid metallic contact with one of the containers, while passing through the ldisk 12 into a threaded recess in the opposite container.

The described switch mayl be mounted in various ways, but preferably in a manner to permit rotation through an angle suflieient to reverse the switch. Thus a mounting plate'or flange 33 isv shown separated from end wall 21 of the inner cup 11 by an insulating sheet 34 and attached in place of insulated screws 35. The flange or mounting 33 may be integral with an axle or other form of holder 36, which may be mounted in a suitable bearing to permit the described adjusting operations.

In cases where there is danger of internal pressure, due for example to heating from excessive switching operations, it may be desirable to provide a safety valve 38, which 'may be of any well` known type, comprising for example a steel ball spring pressed inwardly upon a conical seat, and` Capable of yielding under high pressure. This gives automatic pressure relief from expansion or formation of gas pressure.

The described unitary device is not only rigid but liquid tight, and rugged and strong against breakage; and the circumferentially extened portion or flange of the disk 12 gives protection against liability to accidental shortcircuit across from cup to cup, and danger tothe user.

The Fig. 4 embodiment is a double switch, and its principles can be extended into a multiple switch. At one part of the switch a first pair of line wires 40 are to be connected or disconnected, while at another part a second air of wires 41 are connected or disconnected, y the switch.

One unit or section, namely at the left side of the figure comprises a first or outer container or cup 42 and a second or inner container 43 whichmay be in the form of a metal ring ,rather than a cup, with a separating disk 44 between the two, having an eccentric aperture 45 as before. The right hand portieri of the figure shows substantially corresponding elements, the outer and inner containers 42l and 43fl with the separating disk 44a containing aperture 458. The outer end of the containing cup 42 is shown as consisting of transparent material 46, while the outer end of container 42a may be an integral metal wall 47. The containers 42 and 43 enclose chambers 48 and 49 while the corresponding containers at the other end enclose chambers 43,a

and 49a.v These four chambers respectively carryV portions or bodies of mercury 50, 51, 50a and 51a.

'Thesetwo complete units may be mutually joined to a middle or partition piece or wall 53, composed of insulating material such as bakelite or hard rubber, having left and right flanges 54 and 55, cylindrical in form. The left flange 54 is shown as having a threaded engagement 56 with the container cup 42 while the right flange has similar threaded engagement 57 with the container 42a This arrangement gives a very compact and secure assemblage of parts. Owing to the offset or shouldered contour of the container 42 it is able to press inwardly against the face of the disk 44. The cylindrical container 43 can be pressed between the disk 44 and the partition wall 53. The threaded engagement 56 secures all these parts firmly in position. The entire apparatus may be carried by an axle or stem 59 as before, the same formed with a flange 60 secured to the end wall 47.

The circuit may be arranged through a terminal screw 62 extended into the container 42 and connecting with one of the circuit wires 40while the otherwire 40 is connected to a. terminal screw 63 shown extended through the partition flange 54 and into the cylindrical container 43, thus establishing communication and serving to position the container.- The corresponding arts at the right hand unit bear similar re erence numbers. -Each of the separating disks may have apositioning pin 64 entering recesses in the disk and in the container cylinder 43, thus positioning the disk.

As shown in Fig. 4 the two apertured disks` 44 and 44'L are shown in the same position so that the reversal of the switch will close both circuits, namely through wires 40 and through wires 41. The mode of reversal might be varied. The centralpartition piece 53 is in the nature of a support and .this might be mounted for rotation to operate the switch. Upon inspecting the condition of the switch through the glass end 46 at the left, this shows Lima-rael simply by inverting one of the separating' disks for example the disk 44a so as to bring the positioning pin 64 into engagement with an opposite' recess in the container ring 43, such recess being indicated in dotted lines in the lower part of the figure; or the readjustment could be effected by the cooperation of the terminal screw 63 with a lseries of threaded recesses in the container ring. There mayT be more than two switch sections and theymay readily be timed so that a rotation of the .switch will operate to close the circuit successively through the respective sections.

Fig. 5 shows a modification wherein the arrangement is reversed in that the separating disk 70 is composed of conduct-ing metal, while the opposite cups 71, 72 are composed of insulating material and enclose chambers 73, 74 in which are contained bodies of mercury 75 and 76 both constantly in electrical contact with the disk 70. Asbefore each chamber has a circuit terminal, namely the contact blocks 77 and 78, having their stems extending through the container walls, with exterior terminal devices or nuts 79, 80 to which the line wires 81, 82are attached. In the position shown the circuit is closed through. the contact blocks, themercury and the separating disk, whereas u on inverting the device the mercury will reak contact with the blocks and thus break the circuit. This simle arrangement could be employed for closing and opening two circuits simultaneously by connecting the wire 81 and the disk 70 as part of one circuit and/the wire 82 and the disk 70 as part of another circuit. By then shiftin one of thetwo cups or its contact piece t rough 180, the switch will close one circuit-while opening the other, and vice versa, upon rotation.

Fig. 6 may be considered as a modification of either Fig. 1 or Fi :4, for example Fig. 1, and indicates one of t e cups or containers 10 as constructed in two symmetrical halves 10", 10b secured together by the tightening screws In this case the se arating disk or wall 12b may be of substantially the'internal diameter ofthe container so asyto be clamped firmly in the position shown. This mode of structure and assemblage is in lieu of the 1ongitudinal bolts of Fig. 1 or the screw connection of Fig. 4. Fig. 6 illustrates also that the aperturesvneed not be sectors as in Figls. f

1,-4, but may be of other shapes such as elliptical openings 13", and this figure illustrates'also that there may be a plurality ofthe communicating apertures 13", for examplev two of them spaced opositely. With this arrangement the switc may be rotated always in one direction and will make or close the circuit and break the circuit twice on each rotation. The mercury ma be supplied to a depth as shown at 25,.an above the mercury the space may be filled with an inert gas such as helium 27".

In the case of any of the embodiments the rotation of the switch may be effected either by hand or mechanical connections. Thus at the right side of Figa, surrounding the axle 59 are shown the following elements. A spacin washer contacts the iange 60 and spaces 1t from a'fixed bearing or journal 66 of any usual type. Outside of this is shown a collar 67v pinned to the axle and this collar may constitute the hub of a gear 68 which may be in mesh With-other gears for effecting the desired rotation. Pinned to the axle outside of these elements is shown a handle in the nature of a crank, -which may be employed for effecting the desired rotation.

It will thus be seen that there have been described several illustrative embodiments of the principles of the present invention and attaining the ob'ects thereof. Since various matters of com ination, arrangement, structure and design may be modified without departing from the inventive features, it is not intended to limit the invention to such matters except so far as set` forth 'in the appended cla-im.

What is claimed is: l

Amultiple rotary mercury switch comprising an insulating) disk separating two pairs cham of mercury ers, a metallic ring at each sideof such disk, an apertured insulating disk. 05

against each ring, a metallic cylindrical container against each apertured disk, means holding all assembled, and circuit connec- 'ALFRED vM. DISITELI. 

